Fix UI bugs, Add auto download support

What's Changed

• Update README.md by @devwaseem in #3
• Fix sidebar getting stuck when initial launch, clean unused code by @devwaseem in #7
• Feature/sparkle integration by @devwaseem in #8
• v1.1 by @devwaseem in #9

New Contributors

• @devwaseem made their first contribution in #3

Full Changelog: v0.1.0-beta...v1.1

Initial release

Merge pull request #3 from devwaseem/devwaseem-patch-1

Update README.md

v0.1.0-beta: Add post processing support for `FileDownloadManager`.

MessageDownloadManager now extracts source from json and proceeds saving